Tony Redington brings up the issue of the AOT Paving Program's inward placement
of new guardrails. Here is some background for the topic, including Tony's
orginal email on this issue nearly two years ago.
Table of Contents
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1. Tony Redington's Original Email -- 7/23/97
2. My (Peter Duval) Response to Tony's Email -- 8/17/97
3. VBPC's Letter to Secretary Gershaneck -- 8/18/97
4. A Related Letter to Michael Hedges from VGR -- 9/20/94
1. Tony's Original Email -- 7/23/97
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7/23/97
AN UNINTENDED SAFETY GUARDRAIL CONSEQUENCE--UNSAFETY FOR BICYCLES?--OR WHEN
DOES ONE PLUS ONE EQUAL ZERO?
Larry Hebert, a TACer from Williamstown for the CVRPC, pinpointed a bicycle
safety problem for narrow roads they are given "improvements" in the form of
new guardrail.
Hebert, a trucker, has been a frequent critic of roads without shoulders
for bicycles, and lived the problem a few weeks ago when a tractor-trailer
on VT 110 moved into the opposite lane to avoid hitting a bicyclists with
Hebert operating a large size single-unit dump approaching from the opposite
direction had little choice but to hit the ditch with his truck, which he did.
This lead to the question at the July 22, 1997 TAC meeting about
guardrailing VT 14, where what little shoulder there is being eroded by the
encroachment of new guardrail, being installed as a safety consideration in
order to allow federal funds to participate in paving costs along the
Woodbury stretch discussed. However, there is complaint that the guardrail
being installed narrows the shoulder absolutely, and even when the shoulder
is widened a 0.3 m or so has the net result of narrowing or no change in
shoulder width because a bicyclist dealing with a fence or guardrail
requires a "shy" distance of 0.6 m. So, say, a 0.3 m narrow shoulder with
an expanded shoulder of 0.3 m (0.6 m total), ends up as no benefit at all as
the bicyclist behavior still must use the travel lane of the highway when
adjusting for a 0.6 becomes "shy" space--i.e., one plus one equals zero!
Even more important, the effect of any narrowing of existing travel
lanes/shoulder total usable distance from encroachment of new guardrail
(including shy distance impacts) means decreased net safety to the bicyclist
while presumably providing some protection to the motor vehicle. The
suggestion here is that: any new guardrail installation that after addition
of a shy distance of 0.6 m leaves less than a shoulder of 1.25 m (3.5 ft)
(suggested by the Florida State Bicycle/Pedestrian Coordinator as the newly
researched desirable minimum standard of shoulder outside of the travelway
for bicyclists) should be re-considered in terms of negative safety impacts
on bicyclists. (This means, perhaps, either expanding the shoulder,
relocating the guardrail further away from the shoulder, or abandoning the
guardrail altogether.) Further, if the effect of the new guardrail is to
encroach on the effective shoulder width for bicycles, thereby causing the
bicyclist to move further into the motor vehicle travelway, the net effect
may be increased head-on motor vehicle collisions or opposite direction
vehicles forced off the road.
Finally, future bicycle accidents need to be examined where guardrail
is present so the possible guardrail contribution to the collision can be
assessed.
2. My (Peter Duval) Response to Tony's Email -- 8/17/97
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I always like to look at operations first before blaming road geometry or
facilities as the *cause* of a *crash*.
The example, as described, clearly suggests operator error in the incident
(it's not clear if it constituted a crash). The priniciple at-fault party
is the tractor trailer operator for failing make a safe passing maneuver.
When passing, the onus is placed strictly on the passing vehicle to plan and
execute a safe maneuver.
Speeding (not just the exceeding the posted limit, but also the performance
limits of his truck) on the part of Mr. Hebert may also be a contributing
factor in this crash.
The biker may not be blameless in this, as well. Did the s/he hug the
shoulder, encouraging the tractor trailer operator attempt to pass without
crossing the centerline? Did s/he swerve to avoid the guardrail excessively
as the tractor trailer began the passing maneuver?
Road users can learn or be warned of "dangerous places" in which to operate
with extra care. More likely, this was a coincidence of a tractor trailer
driver and a dump truck driver taking unneccesary risks simultaneously in
the same location. It sounds like the roadway allowed for a controlled
crash and limited damage -- at least to the persons inside the trucks.
Perhaps trucks need to be lighter, smaller, and operate at reduced speeds to
compensate for reckless driving's threat to cyclists and pedestrians, rather
than roads widened and straightened.
That said, the issue is that the highway engineers have applied the
twisted* logic of the "forgiving highway" (long sight distance, comfortable
geometry, clear zones, etc.) unequally. They have placed these soft-to-cars
guardrails right in the path of cyclists and walkers. They have done to
cyclists and walkers exactly what their logic would prohibit them from doing
to cars -- place an immoveable, hazardous obstacle near the line of traffic.
This discrimination must cease.
One last thing, "accidents" implies a helplessly random event. "Crashes"
can be analyzed for fault and contributing risk factors.
--Peter
*If your wondering about the "twisted" part then you haven't seen engineers
blithly ignore their own safety assessments to build big expansive roads and
intersections. Two good examples: the Circ HIghway, which will by design
(unamplified by the effects of released travel demand and induced sprawl)
would kill .05 persons in its first year; and the Industrial Ave./Route 2
intersection expansion, where the cost of life and cost to taxpayers are so
clear that AOT buried the roundabout design internally without ever
announcing that it had been considered.
3. VBPC's Letter to Secretary Gershanek -- 8/18/97
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This is the follow-up to the July 1997 VBPC meeting. Thanks to Tony for help in
drafting the letter to Glenn Gershaneck.
18 August 1997
Secretary Glenn Gershaneck
Vermont Agency of Transportation
133 State Street
Montpelier, Vermont 05633
Dear Secretary Gershaneck:
This letter transmits the unanimous action of the Vermont Bicycle-Pedestrian
Coalition in a July 29, 1997 vote requesting a halt to further guardrail
installation while the danger to pedestrian and bicyclists is assessed and
addressed through a public policy process. The issue of guardrails is not new
(see correspondence, 8/20/94), but recent installations appear to dramatically
encroach on edge of roadways.
The guardrail issue has reportedly arisen in two VAOT regional planning commission
field meetings recently. What is involved is the curtailment of existing space
along our highways for both bicyclists and pedestrians, and the obstruction of
sight lines of drivers overtaking pedestrians and bicyclists.
For bicyclists, there is the need for two feet of "shy" space between them and
obstacles, like walls, trees, signs, utility poles or guardrail. Further,
shoulders bordered by whatever adjacent clear areas can be provided adds to
"recovery" space for bicycles and motor vehicles. The inward placement of
guardrails creates hazardous transitions that cause shoulder-hugging cyclists to
swerve toward the center of the road.
Guardrails, frangible to motor vehicles, pose an unyielding and often sharp hazard
to people, whether biking or walking.
Although the scenic issue has not been raised, a long-delayed New England
Transportation Consortium (NETC) of guardrail types and policies that could affect
the Vermont approach to guardrail installation and could be revised to assure that
these safety concerns are addressed in the scenic byway and tourism context.
It does not make sense to be expanding our highway shoulders by precious inches
only to then lose, in the case of bicycles, two feet in the form of
guardrail-caused shy space and recovery space invasions.
Surely we can agree that guardrail serves a purpose to protect motor vehicles from
driving into sharp drop offs or upgrades, but this should not be done in a manner
that reduces the safe movement of people.
Thank you for your attention in this matter.
Sincerely,
Peter K. Duval, President
cc: Jeanne Johnson, Governor's Highway Safety Program
Governor Howard Dean, M. D.
4. A Related Letter to Michael Hedges from VGR -- 9/20/94
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This letter was written on under GrassRoutes's letterhead four years ago and
provides a history for our concern, (I actually met with Michael Hedges 20 August
1994)
20 September 1994
Michael Hedges
Pavement Management Engineer
Pavement Management Division
Agency of Transportation
133 State Street
Montpelier, VT 05633
Dear Mr. Hedges:
Thank you meeting with me yesterday to discuss the state of pavement in Vermont.
I share your concern about an underfunded paving program.
We talked about the safety improvements, guardrails in particular, that are
required when federal funds are used for paving. I think there are other safety
improvements that could substitute for guardrails, save money, and improve safety
for all road users -- not just the motorists who veer off the roadway.
In my judgment, guardrails do nothing to improve safety for cyclists, walkers and
other road users who are not encased in glass and steel. For these gentle road
users, I think guardrails and other structures may even pose new hazards (try
crashing your bicycle into a car frangible post, for example).
In order to make a highway truly safer for all road users, the operating
speed/design speed ratio must be reduced. As you pointed out in our conversation
yesterday, paving increases operating speed and reduces safety. So why not attack
the problem directly and make highways safe for everyone by:
-Reducing the posted speed on sections that have been repaved. This would also be
a good opportunity for metrification and conversion to international signage.
-Setting up automated speed traps, like the PhotoCop system, to ensure
compliance. These automated traps have the wonderful advantage of being able to
ticket every single speeder, ultimately compressing the distribution of speeds and
bringing all drivers into compliance, not just the 85% best behaved. They
generate revenue, too!
-Using cheap traffic calming treatments to mark the beginning and end of a repaved
segment. Flower box choke points, and arching trees are easy, reversible, ways to
get started on traffic calming for major corridors without a lot of planning &
engineering work.
These positive alternatives to guardrails and clear zones would dramatically
improve safety while maintaining and possibly improving the driving/riding/walking
experience for all.
I look forward to the upcoming public forums and hearing your ideas about
alternatives to guardrails.
Sincerely,
Peter K. Duval
end.
--
Peter K. Duval +1 802 899 1132
98 Sleepy Hollow Road fax: 899 2430
Essex Junction, VT 05452-2798 [log in to unmask]
USA www.emba.uvm.edu/~duval
